BUG: Function Style Conversion Incorrectly Generates Errors

• The Microsoft C/C++ Compiler (CL.EXE) included with: - Microsoft Visual C++ for Windows, versions 1.0, 1.5 - Microsoft Visual C++ 32-bit Edition, versions 1.0, 2.0, 4.0, 4.1, 4.2,

       5.0
  

SYMPTOMS

When calling a class conversion function within a macro, as shown in the code below, the compiler may incorrectly generate the following errors:

  error C2061: syntax error : identifier 'timeVal'
  error C2066: cast to function type is illegal
  error C2059: syntax error : ')'

RESOLUTION

Following are two possible workarounds for this problem:

• Use temporary variables to hold an intermediate result.

        unsigned int tmp1, tmp2;
  

        tmp1 = WORD(timeVal);
        tmp2 = WORD(dateVal);
        m_dwVal = MAKELONG(tmp1, tmp2);
  

• Use a type cast operator instead of a conversion operator.

        m_dwVal = MAKELONG((WORD)timeVal, (WORD)dateVal);
  

STATUS

Microsoft has confirmed this to be a bug in the products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

The following sample code demonstrates this problem.

Sample Code

   /* Compile options needed: /c
   */

   typedef unsigned short      WORD;
   typedef unsigned long       DWORD;

   #define LONG long

   #define MAKELONG(low, high) ((LONG)(((WORD)(low)) |  \
                   (((DWORD)((WORD)(high))) << 16)))

   class CMyDate
   {
   public:
      operator WORD()
      {
         return m_wVal;
      }

   private:
      WORD m_wVal;
   };

   class CMyTime
   {
   public:
      operator WORD()
      {
         return m_wVal;
      }

   private:
      WORD m_wVal;
   };

   class CMyDateTime
   {
      CMyDateTime(CMyDate dateVal, CMyTime timeVal)
      {
         m_dwVal = MAKELONG(WORD(timeVal), WORD(dateVal));

      // This call works in both, even though it is identical.

         m_dwVal= MAKELONG(timeVal.operator WORD(), dateVal.operator
                  WORD());
      }

    private:
      DWORD m_dwVal;
   };